In keeping with widely accepted notions of database design for data warehousing, prior practice in this field has been to use a database design based on a single pre-engineered, a priori data model that is applied to all school systems. Additionally, this fixed data model has invariably been normalized, again in accord with accepted design principles.
Source data in traditional database designs must be mapped to the data warehouse model. Typically, the source data is mapped to an intermediate database where the data is cleaned and checked. Once the intermediate data model is fully populated and the data cleaned, these data are migrated to a final target database. This process is labor-intensive and time-consuming process.
All data fields in traditional data models must be populated before the data warehouse is functional. Mapping of all the data must be completed before the data warehouse is ‘turned on’ and all critical data tables must be loaded to allow for linking across data tables. If certain types of source data have not been collected, or are not readily available, substantial delays and expense occurs in making the traditional data warehouses operational while missing data are collected, cleaned, and loaded.
U.S. Pat. No. 5,991,776 issued to Bennett et al. describes a database system with improved methods for storing freeform data objects of data records in which the system provides each field of a table with a unique ID (“field ID”) for tracking the field and corresponding field IDs stored with the fields of design documents permitting the system to maintain a link between a design document and its table. Date/stamp fields may be provided in '776 to maintain relationships between associated fields. A separate index of the ID s is used, and mapping of data is required therein.
Normalizing the database requires the mapping of every field in each data table to eliminate redundant data fields. This adds more time and expense to the implementation of a functioning system. A normalized database is disclosed in U.S. Pat. No. 5,615,367 issued to Bennett et al. which further teaches a relational database having an automatic linking of data tables by comparing unique keys from one table to the index of another table. The disclosure therein requires each table to be linked through an index of another table instead of directly to that table.
To accommodate new data types or fields, the fixed data model must be engineered at significant cost, and all data must be reloaded. For example, if a school system begins to administer, and collect data on, a new type of standardized examination not contemplated in the original fixed data model, a costly, time-consuming redesign and reconstruction of the fixed data model and data warehouse will be required.
Periodic refreshing of the data warehouse with current-period data encounters the same problems as the initial mapping, cleaning, and loading of data into the fixed data model. This means that on-going upkeep of the data warehouse is required which is time-consuming and expensive. This fixed data model makes data warehousing too cumbersome and expensive to be of use in school systems.
None of the above inventions and patents, taken either singularly or in combination, is seen to describe the instant invention as claimed.